Engine starter



March 1944- J. w. FITZ GERALD 2,343,967

ENGINE STARTER Filed June 19, 1943 WW I Fyz fififleceaseo B Mary E Fi/254 1275 [mm/x c w w Patented Mar. 14, 1944 2,343,967 ENGINE STARTERJohn W. Fitz Gerald, deceased, late of Milwaukee, Wis., by Mary C. FitzGerald, executrix, Milwaukee, Wis., assignor toBriggs & StrattonCorporation, Milwaukee, Wis., a corporation of Delaware Application June19, 1943, Serial No. 491,510

5 Claims.

This invention relates to engine starters and refers particularly to theso-called automatic type of starter wherein the pinion is automaticallypropelled into and out of mesh with the ring gear of an engine to bestarted.

It is an object of this invention to provide an engine starter of theautomatic type which is entirely self-contained and requires no separatepinion stop.

As in a copending application of John W. Fitz Gerald, Serial No.491,511, filed June 19, 1943, of which this is a continuation, it isanother object of this invention to incorporate a degree of resiliencyin the pinion stop and to utilize the resiliency of the resilientdriving connection through which torque is transmitted from the driveshaft to the pinion for this purpose.

With the above and other objects in view, which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed, and more particularly defined by the appended claims, itbeing understood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

The accompanying drawing illustrates one' complete example of thephysical embodiment of the invention constructed in accordance with thebest mode so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a view in side elevation with parts broken away and insection, illustrating an engine starter embodying this invention andshowing the pinion in its normal retracted position; and

Figure 2 is a view similar to Figure 1 but with the parts in thepositions they occupy when the pinion is advanced to its operativedriving posi- Referring now particularly to the accompanying drawing, inwhich like numerals indicate like parts, the numeral 5 designates thedrive shaft of an engine starter motor upon which the starter, indicatedgenerally by the numeral 6, is mounted. The starter has a pinion 1arranged to be moved into and out of mesh with the ring gear 8 of anengine to be started.

As is customary in starters of this type, longitudinal propulsion of thepinion to and from its operative driving position is effected byrelative rotation between it and an actuator 9, the actuator beingdriven from the drive shaft 5 through a resilient driving connection l9.

The driving connection It) comprises a flanged drive head H adapted tobe fixed to the drive shaft as by a set screw 12, a flange I3 on theactuator, and a collar 14 of rubber or other similar material havingcubical elasticity confined between the flanges. A shell [5 clinchedover the flange l3 and engaging over the edge of the flange l6 on thedrive head holds these parts assembled with the rubber collar under adegree of precompression. v

The actuator 9, as is customary, has an externally threaded portion I'Iengaging internal threads in a hub l8 projecting axially from. thepinion; and an anti-drift detent I9 yieldingly holds the pinion againstcreeping forwardly into mesh with the flywheel.

To the extent thus far described, the starter follows the design ofprevious starters of this type. Its distinction lies in the manner inwhich the stop for the pinion is provided.

To this end the pinion is rigidly secured as by brazing to a tube 20.The tube 20 projects axially through and beyond the internally threadedhub I8 and is freely slidable and rotatable on the drive shaft 5. Thetube 20 also passes through the actuator 9 and the resilient drivingconnection Ii] to project into a counterbore 2| in the drive head ll. Atthis point the tube has a stop 22 secured thereon in the form of aspring ring snapped into an annular groove.

The counterbore 2| is large enough to accommodate longitudinal movementof the stop 22 as the tube and pinion travel longitudinally to and fromthe operative driving position of the pinion. Upon reaching itsoperative driving position the stop 22 collides with a washer or disc 23encircling the tube 20 and confined between the flange I6 of the drivehead and the rubber collar [4. Thus as the forward propulsion of thepinion is arrested by the engagement of the stop 22 with the disc orwasher 23, the rubber collar l4 takes up the shock and provides a degreeof resiliency for the pinion stop.

Inasmuch as the transmission of torque through the resilient driveconnection requires a torque transmitting connection between the drivehead and the rubber collar, the washer or disc 23 is nonrotatably butlongitudinally movably connected to the drive head as by tongues 24 onthe periphery of the Washer or disc engaging in slots 25 in the flangel6.

From the foregoing description, taken in connection with theaccompanying drawing, it will be readily apparent to those skilled inthe art that this invention provides a simple and highly ed engagementwith the internally threaded hub of the. pinion so that relativerotation between said parts propels the pinion and the tubeloneitudin-ally with respect to the actuator; a'drive head securable tothe starter motor shaft; a resilient driving connection between thedrive head and the actuator including a part in juxtaposition to thetube; and a stop on the tube adapted to collide with said part to limitaxial movement of the pinion in one direction. I

. 2. In an engine starter: a pinion; a tube fixed to the pinion andprojecting axially therefrom, said tube being adapted to be slidablymounted on the shaft of a starter motor; means for propelling the pinionand the tube axially along the motor shaft and for imparting drivingtorque to the pinion, said means. including a resilient drivingconnection encirclingthe tube and having a driving head adapted forsecurement to the motor shaft, part of the resilient driving connectionbeing in juxtaposition to the tube; and

a'stop' on the tube adapted to collide with said part when the pinionreaches its operative driving position.

3. In an engine starter: a pinion adapted for longitudinal movementalong and rotary movement with the shaft of a starter motor; a pinionactuator; a connection between the actuator and the pinion wherebyrelative rotation between said parts propels the pinion longitudinallyto and from an operative driving position; a drive head adapted to befixed to the shaft of the starter motor; a resilientdriving connectionbetween the actuator and the drive head including a part nonrotatablybut axially movably connected with the drive head, and a body ofelastically deform-able material between said part and the actuator; atube fixed to the pinion and freely slidably projecting through theactuator one direction.

and the resilient driving connection and adapted to be slidably mountedon the shaft of the starter motor; and a stop on the tube adapted tocollide with said part of the resilient drivin connection which isnonrotatably but axially movably connected to the drive head to limitlongitudinal movement of the pinion in the directionto define itsoperative driving position.

4. In an engine starter: a tube adapted to be slidably and freelyrotatably mounted on a drive shaft; a pinion fixed to the tube so thatthe pinion and tube move in unison, said tube projecting axially fromthe pinion; a drive head adapted to be fixed to the drive shaft andhaving a part telescoped over one end portion of the tube; a resilientdriving connection between the drive head and the pinion encircling thetube and by. which the pinion is propelled longitudinally to and fromits operative driving position and torque is transmitted from the drivehead to the pinion; a pinion stop fixed to the end partion of the tubewhich is telescoped within the drive head; and an abutment forming partof the resilient driving connection and in position to be engaged by thepinion stop to limit longitudinal movement of the tube and pinion anddefine the operative driving position of the pinion.

5. In an engine starter: a tube adapted to be slidably and rotatablymounted on a drive shaft;

of the pinion is transmitted to the tube and the pinion and tube move inunison; a drive head adapted to be secured to the drive shaft; aresilient'driving connection between the drive head and the pinion bywhich the pinion is propelled longitudinally to and from its operativedriving position and through which driving torque is resilientlytransmitted to the pinion when in its driving position, said resilientdriving connection encircling the tube and including a body ofelastically deformable material; a stop on the tube; and an abutmentsupported by the body of elastically deformable material and in positionto be engaged by said stop to limit longitudinal movement of the pinionand tube in MARY C. FITZ GERALD, Executria: of the Estate of John W.Fitz Gerald,

Deceased.

